This invention relates generally to protection of pipe against damage to insulation and/or corrosion. More particularly it concerns mounting of the pipe in such manner as to alleviate either or both of these problems.
Pipelines are commonly insulated as by covering them with protective wrapping. In the case of heavy pipe, as for example is used for flowing petroleum or gas, the wrapping operation may be carried out prior to seating of the pipe in a trench, and skids may be used to temporarily support the insulated pipe. It is found that damage can and does frequently occur to the wrap as a result of gouging by edges on the skid members as the pipe is placed on or lifted off the skids, or moves endwise with temperature change.
Inadequate cathodic protection of metal pipelines, leading to corrosion, is another problem which commonly occurs. For example, it is found that the capability of zinc and other anodes, electrically connected with metal pipelines to provide cathodic protection, is diminished at elevated temperatures. Accordingly, when a pipeline is required to pass hot petroleum over long periods, as in artic regions, the pipe and its surroundings are heated by the petroleum and maintained at high temperatures, as for example 130.degree. F. to 150.degree. F., and corrosion can result despite the attempted use of zinc anodes for cathodic protection.